System and Method for Unsupervised and Active Learning for Automatic Speech Recognition

1. A method comprising: identifying, in a database of utterances, transcribed utterances and un-transcribed utterances; selecting, via a processor, transcription candidate utterances from the un-transcribed utterances using confidence scores of the un-transcribed utterances; transcribing the transcription candidate utterances, to yield additional transcribed utterances; and adding the additional transcribed utterances to the database of utterances.

2. The method of claim 1 , the method further comprising: determining the confidence scores using an acoustic model and a language model.

3. The method of claim 1 , wherein word posterior probability estimates are used for confidence scores associated with the database of utterances.

4. The method of claim 1 , wherein the transcribing the transcription candidate utterances is conducted by a human being.

5. The method of claim 1 , wherein the transcribing the transcription candidate utterances is conducted by the processor.

6. The method of claim 1 , further comprising: upon adding the additional transcribed utterances to the database of utterances, removing the additional transcribed utterances from the un-transcribed utterances.

7. A system comprising: a processor; and a computer-readable storage medium having instructions stored which, when executed on the processor, perform operations comprising: identifying, in a database of utterances, transcribed utterances and un-transcribed utterances; selecting transcription candidate utterances from the un-transcribed utterances; transcribing the transcription candidate utterances, to yield additional transcribed utterances using confidence scores of the un-transcribed utterances; and adding the additional transcribed utterances to the database of utterances.

8. The system of claim 7 , wherein the non-transitory computer-readable storage medium stores additional instructions which, when executed on the processor, perform a method comprising: determining the confidence scores using an acoustic model and a language model.

9. The system of claim 7 , wherein word posterior probability estimates are used for confidence scores associated with the database of utterances.

10. The system of claim 7 , wherein the transcribing the transcription candidate utterances is conducted by a human being.

11. The system of claim 7 , wherein the transcribing the transcription candidate utterances is conducted by the processor.

12. The system of claim 7 , wherein the computer-readable storage medium has additional instructions stored which result in the operations further comprising: upon adding the additional transcribed utterances to the database of utterances, removing the additional transcribed utterances from the un-transcribed utterances.

13. A computer-readable storage device having instructions stored which, when executed on a computing device, cause the computing device to perform operations comprising: identifying, in a database of utterances, transcribed utterances and un-transcribed utterances; selecting transcription candidate utterances from the un-transcribed utterances using confidence scores of the un-transcribed utterances; transcribing the transcription candidate utterances, to yield additional transcribed utterances; and adding the additional transcribed utterances to the database of utterances.

14. The computer-readable storage device of claim 13 , wherein the computer-readable storage device has additional instructions stored which result in the operations further comprising: determining the confidence scores using an acoustic model and a language model.

15. The computer-readable storage device of claim 13 , wherein word posterior probability estimates are used for confidence scores associated with the database of utterances.

16. The computer-readable storage device of claim 13 , wherein the transcribing the transcription candidate utterances is conducted by a human.

17. The computer-readable storage device of claim 13 , wherein the computer-readable storage device has additional instructions stored which result in the operations further comprising: upon adding the additional transcribed utterances to the database of utterances, removing the additional transcribed utterances from the un-transcribed utterances.